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Posts Tagged ‘trail running shoes’

La Sportiva Raptor Review

Thursday, February 11th, 2010

La Sportiva Raptor

I’ll admit it: this one surprised me.

When I was first introduced to the Raptor last summer at Outdoor Retailer, I immediately thought of it as Wildcat’s Evil Twin. The similarity between the two shoes was obvious. It seemed like the Raptor looked a bit meaner than the Wildcat and, as I became familiar with the details of the Raptor’s design, I expected it to act a bit meaner than the Wildcat. Still, they look so much alike and have so much common DNA I wondered how different they could really be. You might say I expected the differences between the Raptor and the Wildcat to be more than cosmetic, but not much more. That isn’t really how it turned out.

The Same Platform
(Full Wildcat review here.)

The Raptor is built on the same last, called the Tempo, as the Wildcat. La Sportiva accurately calls out the fit of this last as medium/wide. As a point of comparison, both shoes are considerably more spacious, especially in the heel and midfoot areas, than Sporties built on their Racing last (i.e. Skylite, Crosslite, and Fireblade). So both the Raptor and Wildcat are better choices for runners who have wider feet and/or like to provide for more in-run foot swelling.

The Raptor and Wildcat also have the same basic midsole specs, in terms of both thickness and density. Neither of these are low, flat shoes. Rather, they are built to absorb plenty of shock, especially in the heel. This level of shock absorption can come in handy for some of us all the time (heel strikers), and for pretty much all of us some of the time (during descents, especially long, steep ones).

TPU Heel Stabilizer

The final similarities worth noting are relatively minor: both the Raptor and Wildcat have a TPU heel stabilizer cup and a debris guard between the laces and tongue.

Things Get Interesting

The Raptor differs from the Wildcat in three significant ways.

Upper (f/ TPU Lace Cage)

1.  Instead of a very airy (and somewhat delicate) mesh upper, the upper of the Raptor is made of a more rugged mesh with synthetic leather overlays along the sides of the shoe. These changes add significant protection and durability while sacrificing a bit of breathability. The overlays also provide a solid anchor for the TPU lace cage.

2.  The Wildcat has a 2.4mm EVA cushion in its footbed, which is one of the main sources of the shoe’s relatively plush ride. In designing the Raptor, La Sportiva dropped this element. The result is a significantly firmer, and slightly lower, ride. (Click here to view a cross-section of the Wildcat midsole, including the layer of EVA cushion.)

Outsole

3.  The outsole of the Raptor is made of Frixon XF, whereas the Wildcat — and the rest of Sportiva’s mountain running lineup — features Frixion AT. What does that mean? If you are familiar with any of Sportiva’s other trail running shoes, you already know that an outsole made of Frixon AT equals a very sticky shoe, befitting the company’s cross-disciplinary expertise in climbing shoes. Well, the XF compound is even stickier. It is the same compound Sportiva uses in their approach shoes, and is just one category short of what they use in their flat-out climbing shoes. In other words, the Raptor outsole is seriously sticky.

Trail Manners

In many respects, the Raptor actually behaves a lot like shoes in the “tank” category: its chassis offers a very firm, stable ride, while its upper offers enough protection for even the nastiest trail conditions. The medium-wide fit provides plenty of room for swelling, which the TPU lace cage balances out by enabling a very snug fit all the way around the mid-foot.

This profile is (obviously) very different from the Wildcat, which is more of a plush, lightweight cruiser that really shines on fireroads and other lower-leverage terrain. Where the Wildcat is one of the more pavement-friendly trail shoes around, you won’t really appreciate the Raptor’s virtues until you put it through the ringer. The hairier the trail, the happier these shoes are.

And then there’s this: unlike most tanks, the Raptor is a very, very light shoe, weighing nearly the same as the Wildcat, which is roughly the same as the racy Fireblade and only slightly more than the even racier Crosslite. Interesting twist.

My Opinion

Under most conditions, I personally prefer “less shoe” to “more shoe.” As in, relatively flat and relatively firm. But sometimes I want a bit more heel cushion for long, hard descents. And sometimes, when the outing is likely to include a serious dose of bushwacking, I like a bit more protective upper. On those occasions, the Raptor is quickly becoming my shoe of choice: it’s everything I want from a burly shoe, but significantly lighter and more nimble than what I usually expect from such a rugged shoe.

The Raptor has the same roomy foot environment as the Wildcat, but the lace cage allows me to all-but-eliminate any squirreliness that might come from quick, twisty steps over very technical stuff. Adding considerably to the confidence-inspiring feeling of the Raptor is the XF outsole compound. The Raptor is easily the stickiest trail running shoe I’ve ever laced up — an absolute joy on any trail surface where grip is at a premium. If you’re like me, you’ll find yourself wondering if it’s possible to literally climb walls in them.

My go-to “test lab” includes a semi-long, extremely technical descent on slickrock. In the Raptor, I find myself throwing caution to the wind and taking dicey sections faster than I’ve ever dared before. I just point ‘em downwards and hang on tight!

Wear Note

This was not a long term test (only about 50 miles) so I cannot say anything definitive about the Raptor’s durability, which has been one of the few criticisms I’ve heard of the Wildcat with any consistency. (This should really not be terribly surprising, since the Wildcat design is optimized for relatively low-leverage terrain.)

There is little doubt in my mind that the upper of the Raptor will withstand serious abuse. Less clear, in my mind, is how the midsole will hold up.

Generally, a less dense midsole like that of the Raptor/Wildcat will break down noticeably more quickly than shoes with very dense midsoles (e.g. Fireblades). Less dense midsoles feel “cushy” out of the box, but lose that feeling with the lost “dead space” that comes from repeated impact. This phenomenon is especially noticeable with most road shoes.

So it might seem the loss of “that cushy feeling” should occur with the Raptor at about the same rate as it does to the Wildcat. However, remember that the Raptor does not have a 2.4mm EVA footbed, as the Wildcat does. It’s entirely possible that the breakdown of this particular feature represents a significant part of what Wildcat owners experience when they notice a loss of cushion as the miles accumulate. For that reason, I suspect that the Raptor midsole will retain, over time, more of its cushion (or lack thereof) than the Wildcat. But it’s too soon for me to say for certain.

Manufacturer’s Specifications

Price: $110
User: Unisex
Claimed Weight: 12.28 oz/ 348 g
Last: Tempo 2
Fit: Medium/Wide
Upper: AirMesh/ Synthetic Leather/ TPU Lacing Harness/ TPU Transkinetic Heel Stabilizer
Lining: Mesh (back half and tongue only)
Midsole: MeMlex/ Nylon Molded Flex Transfer shank
Midsole Height (MM): Heel: 28 mm Toe: 16mm Delta: 12mm
SOLE: FriXion®XF/ Impact Brake System™ X-Axis™

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Raptor Store Page (Unisex) >>

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Trail-Specific Shoes, Part 2

Tuesday, February 9th, 2010

In part one of this topic, we looked at the main factors beginner trail runners should consider when deciding whether to opt for trail-specific shoes. This post, also intended to help beginners navigate the world of trail running footwear, outlines from the ground up the main design differences between road and trail running shoes.

(Although beginner trail runners should be aware of the ongoing debate regarding barefoot running, a discussion of that topic is beyond the scope of this post.)

Context

Let’s first briefly revisit the obvious but important point that wilderness trail surfaces aren’t like typical paved or concrete running surfaces. Road running is done on surfaces that provide a consistent, predictable landing pad, while high-leverage trails do not. High-leverage trails are often covered in moisture or loose dirt, or littered with stationary obstacles like roots and rocks. The vertical slope and horizontal tilt typical of high-leverage trails pose additional challenges.

What does this mean for shoe design?

For starters, it means the organizing design principle for trail shoes is fundamentally different from that of road shoes. The “problem” road shoes are designed to solve is at the intersection of repeated hard-surface impact and the individual runner’s biomechanics. Given the nearly identical impact of each foot strike, the primary risk of injury to a road runner is obviously that of repetitive stress.

The approach taken by road shoe designers is to provide considerable cushioning, which is often supplemented with features intended to manage the idiosyncratic running action of different types of runners. Over time, road shoes have evolved into the categories motion-control, stability, and neutral, which are fairly well-defined and understood by most experienced runners.

By contrast, trail running shoes are designed primarily to respond to the trail itself and only secondarily to the runner’s profile and running style.This makes sense for a few reasons.

First, wilderness trails are almost always softer than pavement or concrete, which reduces the impact force of each footstrike. There’s simply less call for cushion.

Second, the biomechanics of the runner’s stride are largely thrown out of their normal repetitive consistency by the trail’s constantly changing nature (unless it’s a really boring trail). Running on some trails looks a lot less like what you see at the Boston Marathon and a lot more like what you see during a punt return at a football game.

Finally, traversing unpredictable wilderness trails at speed considerably increases the risk of injury from a single violent trauma like a sharp poke to your sole, a twisted knee or ankle, a stubbed toe, or a fall.

With this background established, we are now ready to explore the technical differences between road and trail running shoes.

Outsole

Having good traction makes all the difference when you come to a slippery, treacherous section of trail: good trail shoes allow you to confidently attack terrain you otherwise would have to tip-toe gingerly across. Since trail shoes need much better traction than road shoes, their outsoles typically are made from much stickier rubber compounds.

Most also have fairly substantial lugs designed to hook up in loose dirt conditions. However, a deep-lugged tread is not a universally desirable characteristic. Larger lugs sometimes translate into a higher, less stable ride. Also, for exceptionally smooth trails and those featuring a heavy dose of rock, a relatively bald outsole will provide more shoe/trail contact and, therefore, better traction. Beware, also, of lugs that are spaced close together, since mud will tend to get packed in the spaces between them, whereas wide-spaced lugs will be more likely to shed mud. For these reasons, I generally recommend selecting a tread design that provides as deep a lug as the terrain demands and no more.

The rubber compounds used in the outsoles of trail shoes are, as a rule, much denser than those of road shoes. This greatly improves durability and provides a protective barrier between your foot and sharp objects.

Midsole

The midsole of trail running shoes tends to be more protective yet less cushioned than road running shoes. This is primarily a function of the density of the materials used, but the midsoles of many trail shoes also incorporate a rock plate.

Many trail running shoes have a relatively thin midsole, which reflects the preference, nearly universal among trail runners, for a lower, more tactile feel of the trail surface. A thicker midsole adds height and reduces stability, which dampens trail-feel and makes twisted leg joints more likely. In addition to riding lower than comparable road shoes, trail shoes tend to be a bit wider than their road cousins for the same reason.

The combination of a low, confident ride and dense midsole materials means that a trail shoe will generally feel considerably stiffer and more stable than a comparable road shoe. For this reason, it is common for a trail running shoe that feels “in tune” on a technical trail to feel a bit stiff on pavement. It’s a bit like driving a Jeep.

Upper

The uppers of trail shoes also feature a variety of distinguishing elements. One of the most important is the stout toe bumper built into trail shoes. The violence of a stubbed toe mid-trail run is impressive. When it happens — and it will happen — you will be glad to have just a bit more protection where it counts. Most trail shoes also feature a gusseted tongue or “scree guard” to prevent debris from infiltrating the shoe.

Since water is a common element on many trails, the use of Gore Tex or other waterproof membrane is more prevalent in trail shoes than road shoes. However, most trail runners prefer to manage water not by trying to keep it out of the shoe, since that is often futile, but by opting for an airy, well-draining, quick-drying upper.

If you aren’t sure whether your trail conditions call for Gore Tex, consider the rule of thumb that a waterproof upper is better at managing snow and general slop than repeated crossings through shin-deep water.

Bottom Line

All the individual choices that go into the design of road and trail running shoes add up to a pretty significant difference in the way they each perform. In general terms, trail shoes tend to offer a ride that is noticeably lower, firmer, and more stable than road shoes. They also offer improved traction and protection…but not cushion.

Although trail shoes tend to be heavier than comparable road shoes, due primarily to the density of the materials used in their mid- and outsoles, there are plenty of models of hardcore trail shoes that are not particularly heavy or “hiker-y.” Although it is hard to generalize, the typical weight difference between a trail running shoe and a comparable road shoe is in the range of 1-2oz.

That said, when it comes to choosing a trail shoe, I would suggest that trying to link a given road shoe to its trail counterpart is a nearly pointless exercise, since the categories distinguishing trail shoes are considerably less clear-cut than for road shoes and relate to terrain as much as to the biomechanics of running. Like learning any new language, your fluency in trail will really improve as you are able to skip the step of translating in and out of road.

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Trail-Specific Shoes, Part 1

Tuesday, January 19th, 2010

One of the first things many people wonder as they think about trail running for the first time is whether they need trail-specific running shoes. The most common follow-up is: what’s the difference, i.e. what are trail running shoes like? In this post, I will offer my perspective on the first question. In a future post, we’ll look at the latter.

The short answer is that most runners enjoy their time off road more in a pair of trail-specific running shoes than in shoes designed either for road running or hiking. However, the degree of benefit depends a great deal on both terrain and runner. Let’s discuss each in turn.

The Terrain

When someone talks about “trail running,” they could actually mean any of a range of activities. It is therefore helpful to begin by defining the term. As a starting point, let’s consider how ATRA (American Trail Running Association) defines it:

“Although most runners consider trail runs to be strictly an off-road and primarily a mountain experience, our definition of trail runs is fairly broad based to include not only mountain single-track trails but to encompass the oft paved pathways in rural and urban areas. We wrestle with the idea that a trail must deny motor vehicle access for consideration by our association since many out of the way places in the mountains have jeep or four-wheel drive access.”

Based on ATRA’s definition, trail running encompasses an incredibly diverse range of terrain. I have no quibble with this as a philosophical matter; inclusivity is good for the sport. But when discussing appropriate gear, it isn’t specific enough.

When trying to determine the appropriateness of trail-specific shoes, I like to think in terms of “leverage.” The point is to move away from the binary thinking of “trail running/not trail running” in favor of a spectrum. We can further refine leverage as consisting of both physical and technical dimensions.

As you probably suspect, lower leverage terrain has smoother, more predictable surfaces (the technical difficulty dimension) and easier grade changes (the physical difficulty dimension). Foot placement entails little risk of immediate injury. Sustained climbs and descents rarely exceed 5% — 1 foot of elevation change for every 20 feet traveled — and are usually well below this threshold. Examples include natural-surface park paths, rail-trails, and most fire roads, in addition to the single- and double-track wilderness trails that typically come to mind. Per ATRA’s definition, low-leverage trail running may even include paved bike paths.

Low-Leverage Single-Track

By contrast, higher leverage trail running happens on uneven, unpredictable surfaces with significant grade changes, almost always in mountain and other wilderness settings. Primarily, this means double- and single-track where rocks and roots litter the trail. Exposure — the myriad risks associated with being far from help in the face of often extreme natural elements — may be a significant factor. (You know, as opposed to the hazards of sharing a bike path with pre-teens on rollerblades.) Sustained climbs in excess of 5% are common, as are shorter ramps of 15-25% or more.

High-Leverage Mountain Single-Track

High-Leverage Desert Single-Track

The Runner

Athletes who decide to take up trail running bring a range of experiences and expectations to the activity. Common converts include road runners, hikers and backpackers looking to go ever lighter and faster, and multi-sport athletes interested in all forms of human-powered outdoor activity.

The kind of trail running pursued at the outset by a particular athlete will usually be a natural extension of what they already are doing. The road runner is likely to cross over by first mixing some lower leverage trail terrain into his or her current road routine, whereas the lifelong hiker is more likely to tackle difficult terrain straightaway, but probably at a speed only slightly faster than their hiking pace.

Upshot

Now that we have made more meaning of the term “trail running,” it should start to become clear whether trail-specific shoes are a worthwhile investment for the beginning trail runner. If you are thinking about taking only a minor, incremental step from what you are currently doing in terms of terrain, speed, and/or duration, trail-specific running shoes will provide only a limited advantage over the footwear you are currently using. But if you are interested in high-speed, high-leverage trail running, a pair of shoes equal to the task will, for most people, significantly increase both the safety and enjoyment of the experience.

The obvious advice is to try the type of trail running activity most like what you are currently doing, using the footwear you currently use for that activity. If you like it — and, let’s face it, you will — upgrade to specialty shoes, and other trail-specific gear, as you lever up.

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